Emma Raducanu has retired from the quarter-finals of the Korea Open with an apparent left foot injury, after losing the first set 6-1 against top seed Daria Kasatkina.
The Briton was bidding to reach her first semi-final above WTA 250 level since winning the 2021 US Open.
Kasatkina had not lost a set to Raducanu in two previous meetings, including a 6-2, 6-2 win in the Eastbourne grass-court quarter-finals three months ago.
Raducanu had moved into the quarter-finals of the Korea Open after beating Yue Yuan.
“I feel sorry for Emma … it’s easy to get injured, especially deep into these tournaments,” Kasatkina said. “I wish her a speedy recovery.”
The winner of the clash between fourth seed Diana Shnaider and fifth seed Marta Kostyuk will meet Kasatkina in the semi-finals later on Saturday, after rain washed out Friday’s play in Seoul.
Earlier in the day, Brazilian third seed Beatriz Haddad Maia brushed aside lucky loser Polina Kudermetova 6-2, 6-1 to set up a last-four clash with Veronika Kudermetova, who beat Viktoriya Tomova 7-5, 6-3.